Orthopedic procedures for the replacement of all, or a portion of, a patient's joint have been developed over the last thirty years. Currently, the procedures used to prepare the bone and seat the implants are generally referred to as open procedures. For the purposes of this discussion, the term “open procedure” will refer to a procedure wherein an incision is made through the skin and underlying tissue to fully expose a large portion of the particular joint surface. After the initial incision in the skin, the internal wound can be enlarged to fully expose the areas to be prepared. With the wound enlarged, the clinician can perform various pre-surgical planning tasks prior to commencing a joint restoration procedure.
A preliminary step in knee arthroscopy, partial or total knee arthroplasty, femur replacement, and other knee or related orthopedic procedures can include the act of approximating and marking the axis of rotation of one or more condyles. In certain examples, locating and marking the axis of rotation can assist the clinician or surgeon as he or she compares the axis of rotation of the femur relative to the tibia, in order to determine, for example, the varus-valgus angle.